High pressure gas cylinders store industrial and welding gases, carbon dioxide, oxygen, propane, nitrogen, argon, freon, helium, hydrogen, etc. It is also popular to use high pressure gas cylinders for domestic purposes, such as propane gas cylinders for barbecues. Such cylinders are normally installed on the barbecue ready for use. In such installations the valve is exposed and may be opened without lighting the appliance. Consequently, children may inadvertently turn on the gas. If gas is supplied to a barbecue when it is not lit, the gas can leak into the atmosphere, potentially creating a very hazardous situation.
There is therefore a need for a safety cover for use with the shut-off valve on a compressed gas cylinder to protect against access to the valve. Safety covers for use with shut-off valves on compressed gas cylinders are known and described in the prior art.
For example, Griffin in U.S. Pat. No. 4,678,003, entitled SAFETY CAP FOR VALVE ON HIGH-PRESSURE CYLINDER, which issued on Jul. 7, 1987, describes a safety cap for protecting against damage and tampering of the shut-off valve of a high pressure gas cylinder. The cylinder has a threaded neck, such as an acetylene or oxygen cylinder for welding. The safety cap is connected to the neck by a threaded base, which engages the male threaded neck ring of the gas cylinder. A shield for the valve is hingedly connected to opposite sides of the base member. The shield may be closed over the valve and secured in a closed position by positive-lock hinged clamps which engage slots formed in the shield halves.
Another example is described in U.S. Pat. No. 4,352,370 which is entitled PRESSURE VESSEL VALVE HOUSING, issued Oct. 5, 1982 to Childress. This patent describes a valve housing for a gas tank, such as a welding gas tank that includes a pressure regulator. The cover is designed to inhibit tampering and/or illegal appropriation of gas from the cylinder. A clamp strap surrounds a top of the tank and one half of the housing is mounted to the strap. The opposite half of the housing is hingedly mounted to the first half and a hasp mounted to the second half permits a padlock to be inserted through the strap to lock the housing in a closed condition.
The safety covers described above are designed for use with industrial equipment and are therefore unsuited for domestic use with propane cylinders. Consequently, there exists a need for a safety cover for the valve of a propane cylinder designed for use to supply fuel gas to a barbecue. Preferably, the safety cover inhibits access to the valve without reliance on locks or other complex mechanisms that tend to discourage use in a domestic environment.